Project Summary/Abstract The Human Airway Cell and Assays Core provides in vitro models of well-differentiated, primary cultures of human airway epithelia for translational, pre-clinical assays of small molecules and target protein manipulations to judge their efficacy for improving the density and/or activity of WT and mutant CFTRs. These services have an outstanding record of promoting translational assessments of CF pathogenesis and therapy, and they support numerous funded research projects both within and outside the CF Research Center. The overall hypothesis driving these efforts is that impaired ion transport due to missing or defective CFTR compromises the volume and composition of the airway surface liquid (ASL), impeding mucociliary clearance, and leading to infection, inflammation and bronchiectasis. Core A is focused on the production of polarized cultures of human bronchial (HBE) and nasal (HNE) epithelia from CF, non-CF and non-diseased lungs. Studies of channel function, biogenesis and drug-mediated mutant protein correction, performed in polarized HBE cells, are predictive of clinical outcome in the pipeline of therapeutic strategies. This resource supports a large number of funded projects. New methods have markedly increased the Core's capacity to generate air-liquid interface (ALI) cultures, so that HBE availability is no longer rate-limiting. Patient genotype is correlated with CFTR function and drug- induced changes in ion transport. A more directed approach with nasal cells allows for similar analyses on a broader set of rarer genotypes, as embodied in the CFTR2 project. These models are used by P30 investigators who seek to evaluate CFTR biogenesis, the regulation of CFTR and ENaC channels, other relevant transporters, the mechanisms that regulate ASL volume and composition, inflammatory mechanisms arising from airway infections, and treatments to correct CF defects. To support mechanistic evaluations of CF pathogenesis and pre-clinical therapeutics, the Core performs ASL composition, transport and trafficking assays in collaboration with Center members. The interface of HBE and HNE cultures with physiological assays optimizes the use of primary airway cells by Center investigators and for outside academic and industrial interactions. This Core has provided cells, differentiated HBE and assays for numerous studies of new therapeutics. With ion transport as the core defect in CF airways, the successful pharmacological manipulation of channel biogenesis, stability and function, when performed in polarized HBE cells, establishes the translational efficacy dataset needed for advancing a therapeutic strategy to clinical trials.